Detection of Plasmid-Mediated Mobile Colistin Resistance Gene () in Isolates from a University Hospital.

PURPOSE

Colistin represents one of the last treatment options for infections caused by multi-drug resistant (MDR) . The emergence of a plasmid-mediated mobile colistin resistance-1 () gene has raised serious concerns about its potential dissemination among bacteria.

METHODS

In this study, we evaluated the chromogenic medium, CHROMID Colistin Resistance (COLR) agar, for the rapid detection of colistin-resistant using broth microdilution (BMD) as a reference method. We also attempted to detect , , , , and genes, as well as the insertion sequence IS via polymerase chain reaction (PCR), followed by sequencing of gene(s).

RESULTS

Among the 100 studied isolates, 53% of them were colistin-resistant, with higher rate among (75%) as compared to (44.4%). The COLR agar showed 83.2% sensitivity and 97.9% specificity for the detection of colistin resistance. Among colistin-resistant isolates, gene was only detected in four (7.5%) isolates. The IS was not found among positive isolates. Sequencing of gene revealed nucleotide sequence homogeneity with the wild-type gene in BLAST.

CONCLUSION

The COLR agar is a promising phenotypic method for the detection of colistin-resistant . Multiplex PCR followed by sequencing can be used for genes' detection and characterization.